作业帮[(x+y)(x-y)]的七次➗[(-x-y)(x-y)]的五次-2(-xy)的平方,其中x=-2,y=-1求平方差公式解答过程,
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/07 13:55:32
![[(x+y)(x-y)]的七次➗[(-x-y)(x-y)]的五次-2(-xy)的平方,其中x=-2,y=-1求平方差公式解答过程,](/uploads/image/z/2733216-24-6.jpg?t=%5B%28x%2By%29%28x-y%29%5D%E7%9A%84%E4%B8%83%E6%AC%A1%26%2310135%3B%5B%28-x-y%29%28x-y%29%5D%E7%9A%84%E4%BA%94%E6%AC%A1-2%28-xy%29%E7%9A%84%E5%B9%B3%E6%96%B9%2C%E5%85%B6%E4%B8%ADx%3D-2%2Cy%3D-1%E6%B1%82%E5%B9%B3%E6%96%B9%E5%B7%AE%E5%85%AC%E5%BC%8F%E8%A7%A3%E7%AD%94%E8%BF%87%E7%A8%8B%2C)
[(x+y)(x-y)]的七次➗[(-x-y)(x-y)]的五次-2(-xy)的平方,其中x=-2,y=-1求平方差公式解答过程,
[(x+y)(x-y)]的七次➗[(-x-y)(x-y)]的五次-2(-xy)的平方,其中x=-2,y=-1求平方差公式解答过程,
[(x+y)(x-y)]的七次➗[(-x-y)(x-y)]的五次-2(-xy)的平方,其中x=-2,y=-1求平方差公式解答过程,
(x+y)(x-y)=x^2-y^2,
(-x-y)(x-y)=-(x+y)(x-y)=-(x^2-y^2),
∴原式=(x^2-y^2)^7÷[-(x^2-y^2)]^5-2x^2y^2
=-(x^2-y^2)^2-2x^2y^2
x=-2,y=1时原式=-（4-1）^2-2*4*1=-9-8=-17.